The Upper Ordovician Antiplectoceras shamattawaense, from Sweet (1964).

Belongs within: Mollusca.
Contains: Nephriticeratidae, Uranoceratidae, Lechritrochoceratidae.

The Barrandeocerida are a (possibly polyphyletic) group of primitively coiled nautiloid cephalopods found from the Middle Ordovician to the Middle Devonian. Later forms include uncoiled, straight or torticonic species. The group is primarily characterised by a thin-walled siphuncle.

Characteristics (from Sweet 1964, for Barrandeocerida): Cyrtoconic, gyroconic, serpenticonic or torticonic; siphuncle primitively tubular, empty, orthochoanitic, thin-walled; central, ventral, or between centre and dorsum or venter. Many derived species with wholly or partially cyrtochoanitic siphuncle and inflated segments.

<==Barrandeoceratidae [Barrandeoceratida, Barrandeoceratina, Barrandeocerida, Bickmoritidae, Centrocyrtoceratidae]S64
    |  i. s.: Antiplectoceras Foerste & Savage 1927S64
    |           `--*A. shamattawaense (Parks 1915) [=Discoceras shamattawaense]S64
    |         Gasconsoceras Foerste 1936S64
    |           |--*G. pulchellum Foerste 1936S64
    |           `--G. obesumS64
    |         Haydenoceras Flower 1949S64
    |           `--*H. acutum Flower 1949S64
    |         Savageoceras Foerste 1930S64
    |           `--*S. transversale Foerste 1930S64
    |--Barrandeoceras Hyatt 1884 [=Barrandioceras (l. c.), Barrandoceras (l. c.)]S64
    |    `--*B. natator (Billings 1859) [=Nautilus natator]S64
    `--+--Paquettoceras Foerste 1932S64
       |    `--*P. allumettense Foerste 1932S64
       |  |--UranoceratidaeS64
       |  |--LechritrochoceratidaeS64
       |  `--Bickmorites Foerste 1925 (see below for synonymy)S64
       |       |--*B. bickmoreanus (Whitfield 1885)S64 [=Lituites (Ophidoceras) bickmoreanusS64, P68]
       |       |--B. barbensis Foerste 1936P68
       |       `--B. welleri Foerste 1930P68
       `--Centrocyrtoceras Foerste 1926S64
            |--*C. annulatum (Hall 1847) [=Cyrtoceras annulatum, Cy. subannulatum d’Orbigny 1850]S64
            |--C. americanumP68
            |--C. bondiP68
            |--C. duplicostatumP68
            |--C. filosum Foerste 1932P68
            |--C. percinctum Foerste 1932P68
            |--C. relaxum Foerste 1932P68
            |--C. ridleyense Foerste 1932P68
            |--C. rotundum Foerste 1935P68
            `--C. vicinum Foerste 1932P68

Bickmorites Foerste 1925 [incl. Goniotrochoceras Foerste 1928, Leuronotoceras Foerste 1928, Tyrrelloceras Foerste 1925]S64

*Type species of generic name indicated


[P68] Purnell, L. R. 1968. Catalog of the Type Specimens of Invertebrate Fossils. Part I: Paleozoic Cephalopoda. United States National Museum Bulletin 262: 1–198.

[S64] Sweet, W. C. 1964. Nautiloidea—Barrandeocerida. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt K. Mollusca 3. Cephalopoda—General Features—Endoceratoidea—Actinoceratoidea—Nautiloidea—Bactritoidea pp. K368–K382. The Geological Society of America and the University of Kansas Press.

Leave a comment

Your email address will not be published. Required fields are marked *